The present invention relates generally to the field of software defined networking, and more particularly to load balancing in a software defined network.
Information technology (IT) resources, such as computer processors and networks, are being called upon to support ever greater processing demands, leading to the need for server footprints of increasing size to accommodate these expanding workloads. Virtualization provides a way to abstract the components of today's IT resources to consolidate, integrate, and simplify the required infrastructure and reduce the overall cost of IT resource ownership.
Server virtualization technology allows for the configuration and deployment of multiple logical server configurations on a common physical footprint to provide processing and usage benefits beyond those of the physical configuration. The physical server's resources are abstracted to accommodate the concurrent deployment of multiple instances of virtual processors. Each virtual instance, called a virtual machine (VM), is capable of operating a separate operating system (OS) instance and its associated software stacks as if each instance was deployed on a separate physical server. This virtual view offers the benefit of not being restricted by the implementation or configuration of the underlying physical server resources. Each virtual processor instance provides a subset or superset of the various physical server resources that may be dedicated or concurrently shared by multiple VM abstractions. By using processor virtualization technologies, the system's processors can be transparently multi-programmed and multi-processed by a virtualization hypervisor to optimize processor sharing by multiple VM instances, thereby increasing processor utilization.
In traditional IT network architectures there is no centralized network control. Routing tables located locally in network devices, such as switches, bridges, gateways, routers, or firewalls, are individually configured to direct network traffic to neighboring nodes of the network. The network devices may make control decisions and forward network traffic accordingly. Traditional network architectures are contrasted with software-defined networking (SDN), where network traffic routing decisions are centrally controlled and made by a controller that creates tables to define flow paths through the network. The controller decouples control decisions about where traffic is sent from network devices that forward traffic to a selected destination.